Final answer:
To determine the number of atoms in 30.0 g of an element (like potassium), you must first convert grams to moles using the element's molar mass, and then use Avogadro's number to convert moles to atoms.
Step-by-step explanation:
The question is about converting between grams, moles, and atoms for a sample of an element. Specifically, the student is asking how to determine the number of atoms in 30.0 g of an element (presumably potassium, 'K', based on the provided context) and perform conversions in other similar scenarios. To convert grams to moles, the molar mass of the element must be used. For potassium (K), its molar mass is 39.10 g/mol. The number of moles of potassium in 30.0 g is calculated by dividing the mass in grams by the molar mass.
The number of atoms can then be found by using Avogadro's number (6.022 × 10²³ atoms/mol). The number of moles multiplied by Avogadro's number gives the total atoms. To convert atoms to grams or grams to atoms in reverse, the same principle applies but in the reverse order.